e-Key <span id="jodit_selection_marker_1703069603625_18927599390100158" data-jodit_selection_marker="start" style="line-height: 0; display: none;"></span>v3 - Ceratophyll<span id="jodit_selection_marker_1703069603625_035210977652649245" data-jodit_selection_marker="end" style="line-height: 0; display: none;"></span>aceae
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Interactive keys to the identification of seed plants of southern Africa using keys based on plant morphology.

DICOTYLEDON - MAGNOLIIDAE - CERATOPHYLLALES - Ceratophyllaceae

Compiled by R.P. Glen

Description:

  • Submerged aquatic herbs, perennating by buds, sometimes annual, rootless, branches occasionally modified as 'rhizomes'; monoecious
  • Stem branched but not more than 1 branch at a node
  • Leaves in whorls, (3-)6-8(-10) at a node, filiform, once or more dichotomously branched, with 2 rows of minute teeth along ultimate segments, apical segments truncate, tipped with two spines; stipules 0
  • Flowers unisexual, solitary in axil of 1 leaf in a whorl, male and female usually on alternate nodes; perianth lobes 6-13, united at base, strap-shaped or obovate, margin often with a single hyaline spine or lacerated, apex similar to leaf apex; water-pollinated
  • Male flowers subsessile; stamens up to 30 in several whorls on a domed receptacle around pistillode; filaments short or 0; anthers oblong, extrose, 2-thecous, dehiscing longitudinally, immature anthers resembling perianth lobes, margins 1-3-spined; mature anthers detach and float to water surface where they dehisce and shed pollen onto plants below
  • Female flowers sessile or shortly pedicellate; staminodes 0; ovary superior, 1-carpellate, 1-locular, ovoid, tapering into a long style; ovule 1, pendulous, unitegmic
  • Fruit a 1-seeded nut, ovoid or ellipsoid, tipped by persistent style, often with additional marginal and basal spines, also often warty
  • Seed without endosperm
  • x = 12 (aneuploids, polyploidy)

Nomenclature:

  • Ceratophyllaceae
    • Cook: 60 (1990)
    • Wilmot-Dear: 124 (1991)
    • Wilmot-Dear: 125 (1997)

Distribution & Notes:

  • Global: A worldwide family of only 1 genus; ± 6 polymorphic species are presently recognised, each with several varieties or formae
  • Southern Africa: Genus 1, species 2 or 3

References:

  • COOK, C.D.K. 1990. Aquatic plant book. SPB Academic Publishing, The Hague
  • WILMOT-DEAR, C.M. 1991. 161. Ceratophyllaceae. Flora zambesiaca 9
  • WILMOT-DEAR, C.M. 1997. FSA contributions 8: Ceratophyllaceae. Bothalia 27

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